Earlier quoted context omitted.
Related anecdote: I was recently looking at home prices in Chicago, and it seems that people place an enormous value on easy access to the train system. Just eyeballing it, it looked like a house that's less than 1 mile from the nearest train station commands about a $150-$200,000 premium over one that's more than 2 miles from the L.
Driving in downtown Chicago during rush hour is awful. I remember it taking something like 15 minutes just to move a handful of city blocks due to how backed up the on-ramp onto the highway was. Also, are you controlling for the housing type? Condos in high rises (which are much more expensive than detached single family detached) tend to be concentrated near the trains.
There's so many factors that it's hard to make direct comparisons, but for example you can look at homes near the Irving Park blue line stop (which also next to a Metra stop) and then similar home just a few miles West where there are fewer transit options. It's a pretty drastic drop off in home prices for relatively comparable neighborhoods.